Data_fuser.py throws AttributeError

Hello, I am currently working on incorporating the data_fuser.py tutorial on the github so that I can log both gyro and acceleration data. However, after running correctly for a few seconds, it throws the following error and the program crashes:

Traceback (most recent call last):
File "_ctypes/callbacks.c", line 232, in 'calling callback function'
File "C:\Users\gojiman23\AppData\Local\Programs\Python\Python37\lib\site-packages\mbientlab\metawear\metawear.py", line 237, in _write_gatt_char
self._write_char_async(False)
File "C:\Users\gojiman23\AppData\Local\Programs\Python\Python37\lib\site-packages\mbientlab\metawear\metawear.py", line 229, in _write_char_async
next[0].write_without_resp_async(next[1], completed)
AttributeError: 'NoneType' object has no attribute 'write_without_resp_async'

Using: MetaMotionR
Model Number: 5
Firmware: 1.4.4
Hardware: 0.3

Device: Lenovo ideapad 310
OS: Windows 10.0.17134

Any suggestions for how to fix this?